High-Speed Vibrations: Causes and Solutions

Hello,

I've noticed the following problem: My Bora Variant AJM '00 (with approximately 100,000 km) has recently started to exhibit vibrations in the steering wheel (which are noticeable, even if only slightly), starting around 180 km/h.
I noticed this after I installed the summer tires. I didn't drive as fast with the winter tires, so I'm not sure if it's related. I might do a test if necessary.
What surprises me is that the vibrations only occur at such a high speed; at lower speeds, nothing is noticeable. I've only experienced vibrations caused by unbalanced tires at around 100 km/h.
The vibrations are noticeable at a constant speed above 180 km/h and become stronger when accelerating, with the intensity increasing with more load. Searching in this forum has not yielded any relevant results, except for a vague suggestion about the engine mounts.
Okay, the brake discs are quite worn, and there's a very slight vibration when braking gently at speeds above 15 km/h. Could that be related?

Any ideas?

Best regards,
Gerd.

Idea, sure, always...

1) Rebalance and mount the tires.
2) Ensure the rims are mounted evenly and tighten the lug nuts securely. Don't forget to re-tighten them after approximately 100 km (60 miles).

Tip:

When the technician removes the tire from the balancing machine and lets it fall to the floor so he can roll it to the car, he's going to have to put it back on the machine to be balanced again.

Tip:

When the technician takes the tire off the balancing machine and lets it fall to the floor so he can roll it to the car, he's going to have to balance it again...

Why is that?

Sure, here is the translation of the text from German to English:

'MFG' is an abbreviation for 'mit freundlichen Grüßen,' which means 'best regards' or 'sincerely.' It is commonly used in German-language emails and letters.

Okay, I just had a chance to test it out.
The vibrations occur between approximately 170 and 190 km/h. They do not disappear when you release the accelerator and disengage the clutch, so I believe that driving-related factors are not the cause.

When braking from the aforementioned speed down to approximately 80 km/h no vibrations occur. I have tested this multiple times, both with gentle and relatively hard braking.
Could the vibrations also be coming from the braking system? The brake discs are quite worn, but still within the acceptable tolerance range.

Next, I'm going to have the tires balanced. Can you also detect runout on a standard balancing machine? Can the mechanic do this on their own, or do I need to give them a tip?

edit:

Tip:
When the technician takes the tire off the balancing machine and lets it fall to the floor so he can roll it to the cart, he's going to have to balance it again...
Why is that?
I don't understand it either. Every bump in the road causes a harder impact. Then I would essentially have to have the tires re-balanced after every manhole cover. Or would I?

Next, I'm going to have the tires balanced.

You can tell if a wheel has run true by whether or not it can be balanced.
Were the tires not balanced this time?

Why is that?


Because the tire will likely have the same imbalance again, at least to the same extent as before it was balanced. It doesn't even have to fall off completely.
A good mechanic is recognized by the fact that they carefully place the tire down, rather than throwing it.

After this winter rotation schedule, not. Should I have...? Frugality is awesome .

Not after this winter rotation schedule. Should I have...? Frugality is awesome .

Balancing should always be done! Here, balancing with lead adhesive weights costs about €4.50 per wheel... so where is the 'being cheap is good' mentality?
Your entire suspension system will thank you for it...

Well, it's less about being stingy and more about laziness .

Do I need to clean the rim before applying the adhesive weights, or do the technicians have something for that?

Do I need to clean the rim before applying the adhesive weights? Or do the mechanics have something for that?

Rims should be cleaned before being stored. It costs about 1-2€ if you have them steam-cleaned at a car wash...
You can leave the old adhesive weights on; there's a plastic chisel you can use to remove them gently. A technician won't clean them off for you.

The wheels are already mounted, so they're definitely dirty, at least on the inside. Will the weights stay in place?
He should only clean the area where the weights are attached, so that they don't immediately fall off again if they don't stick properly to the dirty rim. In my opinion, this is already part of a proper balancing procedure.

Are you extremely lazy, or what?

Sure, you can also just clean the areas where the balancing weights will go, but how do you know beforehand which areas need to be cleaned before balancing?